Here are our Top 5 gravity-flipping games on iPhone.

We've been eagerly waiting for this indie gem to make its way to iPhone for what feels like ages. VVVVVV is a fiendish retro platform-puzzler that sees you working your way through a labyrinthine world by flipping from floor to ceiling.

Hook Worlds is essentially four fast-paced endless-runners in one package. The ability to swing from a grappling hook is the one common point, but one of these games lets you flip gravity on its head, which makes it arguably the most interesting of the lot.

One of the most popular gravity-flipping games out there, Gravity Guy is a no-nonsense endless-runner with a gravity-flipping twist. It still feels fresh, thanks largely to a brilliant same-handset multiplayer mode for up to four players.

Gravity.Duck is a lot slower and more considered than most of the other games on this list, and it also throws in an extra twist. As well as flipping between the floor and ceiling, you find yourself walking your pixel-art duck up the walls.

Flip Runner! presents the whole gravity-flipping endless-runner thing a little differently from the likes of Gravity Guy. Here, you're running along a single central platform. And when you jump, you disappear off the top of the screen and re-appear upside down on the other side of the platform. As if the whole gravity-flipping concept wasn't sufficiently brain-frying...